In a paper conveying apparatus of an image reading apparatus, image copying apparatus, etc., sometimes a jam occurs when the paper moves along the conveyance path. In general, a paper conveying apparatus is provided with the function of determining whether a jam has occurred by a paper being conveyed to a predetermined position inside the conveyance path within a predetermined time from the start of conveyance of the paper and of stopping the operation of the apparatus when a jam has occurred.
On the other hand, if a jam occurs, a large sound is generated in the conveyance path, so the paper conveying apparatus can determine whether a jam has occurred based on the sound which is generated on the conveyance path and thereby detect the occurrence of a jam without waiting for the elapse of the predetermined time.
A paper feed apparatus has been disclosed which has a microphone which detects a sound generated in a paper conveyance path, pre-processes the signal of the sound detected by the microphone, and detects a jam of the paper based on the pre-processed sound signal (see Japanese Laid-Open Patent Publication No. 2012-193040).
Further, a ray measuring apparatus is provided at which a peak detection circuit is provided for detecting the peak value of the measured signal based on rays from a sample (see Japanese Laid-Open Patent Publication No. 2007-121189).